Elisabeth Jeffries explores various methods that could help decarbonise UK heavy industry
Furnace temperatures in glass factories require peaks as high as 1,575°C as molten glass is moulded into solids. Fuelled by gas or oil, it is no wonder they are a key target in the UK government's industrial decarbonisation challenge to reach net-zero emissions by 2050.
A £50m plant planned at St Helens, Merseyside by non-profit industrial consortium Glass Futures is due to review the process. Trials at the plant will consider alternative fuel systems such as hydrogen, biofuels and hybrid fuel melting technologies, and could reconfigure aspects of the system linked to fossil fuel use. If the findings prove viable, it could radically alter traditional glass industry processes. The plant has received £7.1m in government funding, with more expected from Liverpool City Region Combined Authority.
Researchers need to resolve a range of questions before making the fuel switch, as Richard Katz, founding director of Glass Futures, explains: “Running a glass factory on an alternative fuel could affect raw materials used as well as production efficiencies, changing the fundamentals of manufacturing techniques.“
Reducing industry's natural gas use is critical if the UK is to reach national net-zero targets by 2050, so the glass sector's procedures have come under close examination. Though larger than the cement industry by turnover, it has received less attention in terms of carbon intensity. Strategists at UK Research and Innovation (UKRI), which channels much of the government's decarbonisation research funding relating, now include the industry as a key target. “It's a foundation industry and widely used across the UK economy,“ points out Bruce Adderley, director of the Industrial Strategy Challenge Fund.
Along with industries such as steel and cement, as well as the energy sector, the team aims to revisit a range of renewable and low-carbon sources or vectors that are appropriate for carbon-intensive players. The aim is to pinpoint collaborative opportunities and synergies at Britain's main industrial clusters, such as Grangemouth, Teesside, Merseyside, Humberside, and the manufacturing valleys of South Wales.
The use of hydrogen for energy production is one key option. Norwegian oil company Equinor is leading the Hydrogen to Humber Saltend project, which aims to develop a full-scale facility for producing hydrogen from natural gas in combination with carbon capture and storage (CCS). The project will enable industrial customers in Saltend Chemicals Park, where the plant is based, to fully switch over to hydrogen, while the park's power plant moves to a 30% hydrogen-to-natural gas blend. Equinor states that, as a result, the park's CO2 emissions will reduce by nearly 900,000 tonnes per year.
“Reducing industry's natural gas use is critical if the UK is to reach national net-zero targets by 2050“
One of the more established hydrogen production procedures, 'blue hydrogen', involves reforming methane into hydrogen and CO2. Though it could make a contribution to the net-zero target, it has sparked controversy over its reliance on fossil gas, as well as its dependence on CCS – a technology not yet widely available. Blue hydrogen is being given a major push by the UK government. A key challenge for scientists is optimising CCS processes – at least until hydrogen can be made more cheaply from renewable energy ('green hydrogen'). That means reviewing the gas infrastructure, as well as the CCS technologies themselves.
Of course, CCS is possible directly from gas sources, but hydrogen could be appropriate for other reasons. “Capturing CO2 from natural gas is certainly possible, and indeed forms part of the portfolio of projects associated with the industrial decarbonisation challenge,“ says Bryony Livesey, challenge director at UKRI. “That will work well for power production using gas to produce electricity.“ However, she emphasises the need for hydrogen to provide an alternative fuel for various heating processes (including domestic heating) for which capture of the CO2 is impractical: “The current infrastructure is intended to move gas, so we need to ensure it can be designed appropriately to incorporate hydrogen.“ That requires not only allowing the potential for hydrogen made from gas, but also designing in the eventual distribution of hydrogen from renewables in future.
Though a few oil companies have run pilots or applied CCS in specific settings, it is not yet available at large scale, nor immediately adaptable across industry. Improving CCS is thus a major consideration for full decarbonisation.
“To go from pilot scale to capturing hundreds of thousands of tonnes of CO2 each year is a big step,“ notes Sheena Hindocha, knowledge transfer manager in materials chemistry at UK innovation organisation the Knowledge Transfer Network.
A key part of improving CCS is optimising solvents. A class of solvents called liquid amines is considered suitable for CCS use, but further progress is required for its wider use. “The amount of CO2 captured using the solvents is not high enough,“ says Hindocha. “Scientists are looking at new ways to capture more CO2 in a concentrated form.“ Major players such as the power group Drax are among the companies and organisations investigating ways to improve solvents or find other applications.
Deep Branch Biotechnology, a tech start-up based at Nottingham University, plans to build a pilot plant within Drax's Carbon Capture Usage and Storage Incubation Area at its power station in North Yorkshire. This will extract flue gases from the power station's renewable electricity generation; the gases will be fed to microbes, which can make single-cell proteins for use in fish food and agricultural livestock feeds.
In the transport and energy sector, researchers are trying to continually improve energy charging and storage systems in order to keep up with the demand for renewable energy infrastructure, as well as the requirement for cleaner mobility.
According to Professor Paul Shearing, chemical engineering principal investigator at University College London (UCL), lithium-sulphur batteries will follow lithium-ion batteries to help meet energy storage and distribution requirements: “Lithium-sulphur batteries provide particularly compelling benefits around cost, energy density per unit weight and safety.“ Among the factors that need to improve, he suggests, are recyclability, cost, energy density, power density and safety.
Lithium-ion batteries may have reached capacity when it comes to fulfilling societal needs, Shearing adds. He suggests that lithium-sulphur could provide useful logistical solutions: “When you consider the shipment of large quantities of lithium-ion batteries, which has some challenges, there are improved safety aspects when it comes to lithium-sulphur because we can ship these cells at zero state of charge.“
UCL is working with seven industrial partners and six other universities in a £55m project known as LiSTAR, funded by the Faraday Institution. It is a considerable sum for a research project; coupled with private sector investment and the increased research funding announced by the government in 2017 (bit.ly/325bFDM), it shows that major resources are now being funnelled into the transformation of industry.
£7.1m A pilot plant in St Helens has received £7.1m from the government to trial alternative fuel systems in glassmaking
900k Hydrogen to Humber Saltend is predicted to reduce Saltend Chemicals Park's CO2 emissions by 900,000 tonnes per year
£55m The Faraday Institution is funding the £55m LiSTAR project investigating the potential of lithium-sulphur batteries
Elisabeth Jeffries is a freelance journalist.
Picture credit: iStock